Intangible Assets

12 Months Ended

Dec. 31, 2013

6.	Intangible Assets

Intangible assets consisted primarily of manufacturing process and customer relationships related to our 2006 acquisition of Rhein. The manufacturing process derives from the methods for making proteins in Hansenula yeast, which is a process we use to make a key component in the production of hepatitis B vaccine. The customer relationships derive from Rhein’s ability to sell existing, in-process and future products to its existing customers. Purchased intangible assets other than goodwill are amortized on a straight-line basis over their respective useful lives. The manufacturing process and customer relationships were amortized over their estimated useful lives of five years. Both the manufacturing process and customer relationships intangible assets were fully amortized as of the year ended December 31, 2011. Amortization of intangible assets was zero for the years ended December 31, 2013 and 2012, and $0.3 million for the year ended December 31, 2011.